<?php

class TBT_Enhancedgrid_Model_System_Config_Source_Columns_Show
{
    public function toOptionArray()
    {
    
        $collection = Mage::getResourceModel('eav/entity_attribute_collection')
            ->setEntityTypeFilter( Mage::getModel('eav/entity')->setType('catalog_product')->getTypeId() )
            ->addVisibleFilter();
        $cols = array();
        $cols[] = array('value' => 'id',   'label' => 'ID');
        $cols[] = array('value' => 'type_id',   'label' => 'Type (simple, bundle, etc)');
        $cols[] = array('value' => 'attribute_set_id',   'label' => 'Attribute Set');
        $cols[] = array('value' => 'qty',   'label' => 'Quantity');
        $cols[] = array('value' => 'websites',   'label' => 'Websites');
        foreach($collection->getItems() as $col) {
            $cols[] = array('value' => $col->getAttributeCode(),   'label' => $col->getFrontendLabel());
        }
        return $cols;
    }
}